Slowing down to count and breathe has a calming effect in your brain and body. 

Box breathing is used to calm an over anxious mind, and notice clarity after. 

Box breath counting is also helpful to use to fall asleep, as you count you retrain your brain to slow down too. 

Inhale through your nose, and exhale out of your mouth with a little more effort than normal. Placing one hand on your belly just above your navel and breath with your diaphragm to activate your parasympathetic system.